Enclosed portable generators such as portable inverter generators are known and continue to gain popularity because of their relatively compact and lightweight configurations. Maintaining components of the portable inverter generators within acceptable operating temperatures can prove challenging. Such acceptable temperature maintenance challenges have been additionally complicated by recent efforts to make portable inverter generators even smaller and lighter within the same power output classes. Attempts have been made to address the acceptable temperature maintenance challenges by incorporating complex passages routed through the portable inverter generators to separately directed discrete airflows to different components. These tend to add to the overall cost and complexity of the portable inverter generators and their assembly.
Therefore, it is a primary object and feature of the present invention to provide an airflow system for an enclosed portable generator such as an inverter generator of a compact configuration that is cost effective.
It is a further object and feature of the present invention to provide an airflow system that reduces sound emission through a respective portion of the portable inverter generator.
The present invention is directed to an airflow system for an enclosed portable generator that efficiently cools components of the portable generator by collecting an airflow through a single opening and directing the entire airflow past a heat generating component such as an inverter module assembly before releasing the airflow in an unrestricted manner into an open interior space of the portable inverter generator. Other components of the portable generator use the air from the common open interior space for respective cooling. This allows for improved operation of components of the portable generator through efficient collection and direction of cooling air.
According to one aspect of the invention, an intake plenum system of an enclosed portable generator has a single intake plenum body that directs airflow into the generator. The intake plenum system is configured to collect intake air from outside of the enclosure and directs all of the collected air over the heat generating component such as an inverter module assembly or over cooling fins of an inverter heat sink. A bottom portion of the intake plenum body or an inverter module assembly duct collects air after cooling the inverter heat sink and directs flow into a common open interior space within the housing and toward secondary components such as an engine and alternator intake fan(s).
According to another aspect of the invention, the plenum body is configured to collect and direct an intake airflow across the inverter module assembly and is configured as an acoustic damping element preventing internal engine noise from line of sight egress. This reduces sound levels from the front of the generator by limiting sound egress with the plenum body presenting various spaced apart transversely stacked wall segments that present sound damping baffles toward a front wall of the housing.
According to another aspect of the invention, the airflow system is incorporated into an enclosed portable generator. The enclosed portable generator may be a portable inverter generator with a housing having interconnected walls defining an open interior space. The housing encloses an internal combustion engine driving an alternator operably connected to an inverter module assembly for producing AC (alternating current) power. The airflow system includes an intake plenum system directing an intake airflow into the enclosure for cooling the inverter module assembly. The intake plenum system, including a plenum body, has an intake end defining an intake opening corresponding to an intake plenum system point of entry. The point of entry at the plenum body intake opening receives air through a housing wall(s) as the intake airflow. An outlet end of the plenum body is arranged downstream of the intake end. The outlet end of the plenum body includes an outlet opening corresponding to an intake plenum system point of exit delivering the intake airflow out of the intake plenum system substantially unrestricted into the open interior space of the housing. Substantially all of the air in the open interior space of the housing may enter the open interior space of the housing through the intake plenum system.
According to another aspect of the invention, the plenum body intake opening may be misaligned with respect to the inverter module assembly. The plenum body intake opening may be arranged at the wall(s) of the housing at a position that is height staggered with respect to the inverter module assembly. The plenum body intake opening receives air through the front wall at a location that is arranged higher than a projected height of the inverter module assembly relative to the front wall and thus spaced farther from a bottom wall of the housing than the inverter module assembly. The plenum body and the inverter module assembly may be mounted to a common bracket extending vertically within the housing, for example, by way of weld studs defining locations of the plenum body and the inverter module assembly within the housing.
According to another aspect of the invention, the plenum body may include an inlet duct defining the intake end of the plenum body. The inlet duct extends from the plenum body intake opening toward the inverter module assembly. An inverter module assembly duct defines the outlet end of the plenum body and extends from the inlet duct toward the interior space the housing.
According to another aspect of the invention, the inlet duet and the inverter module assembly duct may be arranged at a non-perpendicular angle with respect to each other. At least a portion of the inlet duct may extend angularly with respect to the inverter module assembly. At least a portion of the inverter module assembly duct may extend parallel with respect to the inverter module assembly. The inverter module assembly duct may include a first wall segment arranged substantially parallel to a first surface of the inverter module assembly and a second wall segment arranged substantially parallel to a second surface of the inverter module assembly. The inverter module assembly may have a first side facing toward the open interior space of the housing and a second side facing away from the open interior space of the housing. The inverter module assembly duct may cover the second side of the inverter module assembly and include an outer wall segment transversely spaced from the second side of the inverter module assembly. This restricts flow of the intake airflow between the second side of the inverter module assembly and the outer wall segment of the inverter module assembly duct to flow longitudinally with respect to the second side of the inverter module assembly.
According to another aspect of the invention, the inverter module assembly duct includes side wall segments extending from the outer wall segment of the inverter module assembly duct toward and overlapping at least a portion of the inverter module assembly. The inverter module assembly may be at least partially nested within the inverter module assembly duct, with the inverter module assembly duct fitting in a cap-like manner over a forward facing surface of the inverter heat sink.
According to another aspect of the invention, the inlet duct is defined by multiple operably and releasably connected components. The inlet duct includes an inner wall segment connected to the inverter module assembly and an inlet duct outer wall segment connected to the housing front wall. Side wall segments of the inlet duct extend from the inner wall segment and collectively define a channel with a channel opening between the inlet duct side wall segments. The inlet duct outer wall segment is removably received between the inlet duct side wall segments, spanning across the channel opening to close the opening to form a closed perimeter wall arrangement of the inlet duct when the housing front wall is removably connected to the remainder of the housing. The housing front wall may have an outwardly facing surface and include a pocket recessed into the outwardly facing surface, extending inwardly toward the open interior space of the housing. At least a portion of the housing front wall pocket may define the inlet duct outer wall segment. The housing front wall pocket may include a pocket upper wall. The pocket upper wall may extend angularly from a perimeter extending about an opening of the housing front wall pocket facing away from the open interior space of the housing. The pocket upper wall may extend generally parallel to and spaced from the inlet duct inner wall segment. In this way, part of the inlet duct is defined by the front wall in conjunction with the respective portions of the plenum body, such as at the upper angled portion(s) of the plenum body.
According to another aspect of the invention, the inlet duct narrows from its inlet opening that initially receives the airflow from outside the enclosure to its outlet opening that releases the airflow into the inverter module assembly duct. This provides a scoop-like configuration of the inlet duct that can collect a relatively large volume of air and concentrate it into the airflow, which can increase the velocity of the airflow through the inverter module assembly duct in a venturi-like manner.
Other aspects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.